CONDUCTOR PASTE

PROBLEM TO BE SOLVED: To provide conductor paste which can improve the bonding strength between a conductor pattern and a ceramic substrate and has high electrical conductivity. SOLUTION: When a conductor pattern 2 is formed on a multilayered alumina board 1 by using conductor paste composed of tungsten, the coefficient of variation of the particle size distribution of conductor particles is adjusted to 0-50%. When the coefficient of variation is adjusted in such a way, the width of the particle size distribution becomes narrow and the conductor particles cannot be charged compactly. During the course of a sintering process, therefore, a glass component contained in a laminated green sheet body enters into the gap of a metallic conductor layer and the conductor patters 2 is firmly bonded to the board 1. Moreover, since the particle size distribution of the tungsten conductor particles is adjusted so that particles of 1-5 μm in size may occupy 90-100% of the paste when the conductor patter 2 is formed on the board 1, the width of the particle size distribution becomes narrow and the conductor particles cannot be charged compactly. Therefore, the pattern 2 is firmly bonded to the board 1 and becomes to have high electrical conductivity.